This invention relates to a hood assembly for use in an automotive vehicle, and more particularly to a hood assembly incorporating inflatable elements for expansion during an impact event.
It is well known in motor vehicles to utilize a hingeable hood disposed in the region between the passenger compartment and the forward bumper of the vehicle. Such hood structures may be opened so as to permit access to an underlying compartment which may store the engine of the vehicle in vehicles incorporating a forward engine design or a luggage storage compartment in vehicles which incorporate a rear engine design. The hood portion of the vehicle is typically formed from a relatively thin sheet of metal such as thin gauge steel which may be molded to the appropriate contour corresponding to the overall vehicle body design. The exterior of the hood portion which constitutes the show surface thereof is typically coated with one or more coats of primer and paint for enhancing both the aesthetic character and the corrosion resistance of the underlying material. Due to the relatively thin nature of the material forming the hood portion, a support structure such as a contoured plate with stamped rib supports typically extends across the underside of the hood portion so as to provide a degree of dimensional stability to the structure.
In the event of a collision, it may be desirable for the hood to have the ability to absorb energy thereby dissipating the force to which persons involved in the collision event may otherwise be subjected. The desirability of such energy absorbing character may be particularly important if the collision involves direct contact between the hood and a pedestrian, bicycle operator, motorcycle operator, or other persons at the exterior of the vehicle. During such a collision event, it is believed that substantially fixed elements underlying the hood such as batteries, engine components and the like may give rise to hard surfaces across the expanse of the hood which may resist deformation and corresponding energy absorption. In addition, structural elements peripheral to the hood such as fenders and the so called xe2x80x9cscuttle areaxe2x80x9d immediately below the windshield may also provide relatively poor energy absorption.
In the past it has been proposed to displace impact regions of the hood away from underlying structures by the introduction of a high pressure gas beneath the impact surface of the hood. One such structure is illustrated and described in U.S. Pat. No. 5,934,743 to Nohr et al. the contents of which are incorporated by reference as is fully set forth herein.
This invention provides advantages and alternatives over the prior art by providing an automotive hood assembly which incorporates an arrangement of one or more inflatable gas receiving cushions disposed in underlying relation to the exterior of the hood assembly and which are expansible to an inflated condition to force the exterior surface outwardly to an impact absorbing configuration. The inflatable gas receiving cushions may be configured to extend outboard from beneath the hood exterior upon inflation so as to provide a cushioned covering relation across exterior portions of the vehicle including portions of the windshield, the scuttle area directly beneath the windshield and side fenders. The displacement of the outer portion of the hood assembly is preferably limited by an arrangement of extensible tethering elements.
These advantages are accomplished in a potentially preferred form of the invention by providing an automobile hood which extends in a region between the passenger compartment and a forward bumper of the automobile. The automobile hood assembly includes a relatively thin deformable exterior defining an outer show surface and an underlying support structure. Disposed between the exterior member and the underlying support structure is an arrangement of one or more inflatable cushions in fluid communication with one or more gas emitting inflators. Upon receipt of an activation signal from a sensor, inflation gas is introduced into the cushion which inflates outwardly away from the underlying support structure thereby causing a corresponding outward deformation of the exterior hood structure. If desired, the arrangement of gas accepting cushions may be such that the inflated expansion provides a degree of coverage across surfaces of the vehicle outboard of the exterior hood member. An arrangement of one or more extensible tethering elements preferably limits the degree of outward expansion of the exterior portion of the hood. The forced outward movement of the exterior portion of the hood assembly gives rise to an extended surface profile thereby leading to an enhanced ability on the part of the hood assembly to absorb energy through collapsible deformation upon impact by a pedestrian or other foreign body.
According to an aspect of the present invention it is contemplated that a plurality of inflatable expansible cushions may be utilized so as to provide deformation forces across different portions of the hood assembly. Of course, a single inflatable cushion may also be utilized if desired.
According to another aspect of the present invention, it is contemplated that one or more of the expansible cushions utilized may be configured to expand to positions outboard of the exterior hood surface upon inflation thereby providing inflated coverage across regions such as the windshield, the scuttle area directly beneath the windshield, the forward pillar structures adjacent to the windshield and the fenders disposed along the sides of the hood assembly. Of course, it is also contemplated that the inflatable cushion may remain entirely beneath the exterior hood surface if desired.